淡水亚硝酸盐样品最佳保存条件的探讨  

The Best Storage Conditions for Determination of Nitrite in Freshwater Samples

作　　者：肖红伟 艾文强[2] 肖化云 罗笠 郭威[1,2] 孙启斌 黄启伟 曾梓琪 

机构地区：[1]东华理工大学江西省大气污染成因与控制重点实验室,江西南昌330013 [2]东华理工大学水资源与环境工程学院,江西南昌330013

出　　处：《环境保护科学》2017年第6期45-48,54,共5页Environmental Protection Science

基　　金：国家自然科学基金资助项目(41663003;41425014);东华理工大学校科技创新团队科研启动基金项目(DHKT2015101);东华理工大学博士科研启动基金项目(DHBK2015327);核资源与环境重点实验室自主基金(Z1609)资助

摘　　要：亚硝酸盐(NO_2^-)是自然界中生物地球化学氮循环重要关键物质,但不易保存。文章讨论了不同pH条件下对NO_2^-浓度测定的影响和不同储存条件下NO_2^-浓度的变化,并确定最佳保存条件。结果表明,当水样品调节pH>10,NO_2^-测定浓度偏低;而pH为自然或酸性时,对NO_2^-浓度测定几乎没有影响;HgCl_2的加入对测定结果不产生影响。但在长期保存时,pH为酸性时(pH=2),随保存时间增加,NO_2^-浓度快速下降。因此碱性条件下不适合测定,而酸性条件下不适合保存,并且建议野外采完样品后立即加入HgCl_2保存NO_2^-,并于60d内测定NO_2^-浓度。Nitrite is a key important substance in the natural cycling of biological geochemistry but hard to save.In this study,the effects of different pH conditions on NO2^- concentration determination and different storage conditions on the NO2^- concentration variation were discussed and the best storage conditions were identified.The results showed that the determined concentrations of NO2^- were lower when pH values of the samples were higher than 10,while the concentrations of NO2^- were almost not affected when pH values were natural or acidic.Addition of HgCl2 into the samples did not affect the measurement results.However,the concentrations of NO2^- dropped rapidly within a long-term storage when the samples were acidic（pH=2）.Therefore,it was not suitable for determination of NO2^- under alkaline conditions and for storage under acidic conditions.When the field samples were collected,it was suggested that HgCl2 be immediately added for NO2^- storage and NO2^- concentrations be determined within 60 days.

关 键 词：亚硝酸盐 PH 温度 保存时间 

分 类 号：X830.2[环境科学与工程—环境工程]